Switching From Reference Trastuzumab to Biosimilar for HER2 Positive Breast Cancer May Not Affect Infusion Reaction, Cardiac Dysfunction

Switching from reference trastuzumab to biosimilar trastuzumab may not have a significant effect on the frequency of infusion reaction expression, or the occurrence of cardiac dysfunction among patients with human epidermal growth factor receptor type 2‑positive (HER2-positive) breast cancer, according to the findings of a safety survey published in Molecular and Clinical Oncology.

Trastuzumab “requires a particularly careful response to infusion reactions and monitoring for cardiac dysfunction,” wrote Tomoya Abe, MD, Saitama Cancer Center, Ina‑machi, Saitama, Japan, and coauthors. In this study, “we decided to focus on the patients who selected adjuvant therapy with paclitaxel plus trastuzumab as initial therapy.”

The study consisted of a safety survey of 9 eligible patients with HER2-positive breast cancer treated with trastuzumab plus paclitaxel at the Saitama Cancer Center in Saitama, Japan. Patients included in the study received treatment between April 2018 and March 2022.

The investigators aimed to determine the safety of biosimilar trastuzumab by evaluating the incidence of infusion reaction and changes in cardiac function after switching from reference to biosimilar trastuzumab in the first treatment paclitaxel and trastuzumab regimen. These changes were investigated in patients who switched from reference trastuzumab to biosimilar trastuzumab and continued treatment (the switching group).

The study authors found that among the 2 groups (reference vs biosimilar trastuzumab), there were no significant difference in the expression of infusion reaction (P > 0.999). In the switching group, infusion reaction associated with switching did not occur in all 9 eligible patients. Left ventricular ejection fraction was used to assess cardiac function, and no patient in either group experienced a significant decrease in left ventricular ejection fraction with treatment, which indicates that there was no effect of switching on the decrease in left ventricular ejection fraction.

“These results suggested that switching from reference to biosimilar trastuzumab may not have a significant effect on the frequency of [infusion reaction] expression or the occurrence of cardiac dysfunction,” the study authors concluded.

“This study has some limitations,” they added, including that this study is a retrospective observational study with a small sample size in a single center.

Source:

Abe T, Sagara A, Okada D, Matsuzaka K. Safety survey on infusion reaction and cardiac dysfunction when switching from reference trastuzumab (HERCEPTIN^®) to biosimilar trastuzumab (Trastuzumab‑NK) in the treatment of HER2‑positive breast cancer. Mol Clin Oncol. 2023;18(5). doi:10.3892/mco.2023.2637